Electrical power storage apparatus

Abstract

An electrical power storage unit has one or more metal-gas electrical cells, each cell including a pair of generally planar outer electrode units configured to define therebetween an interior space for containing an electrical power storage medium and an inner electrode unit mounted between the pair of outer electrode units so as to be in electrically conductive contact with the electrical power storage medium and define a plurality of volumes each having a pair of open ends, each open end facing an adjacent outer electrode unit. The power storage medium is a slurry containing active metal particles and an electrolyte solution. The inner electrode unit is configured for removable insertion within the interior space. The volumes defined by the inner electrode unit are configured so as to contain portions of the power storage slurry such that removal of the inner electrode unit from the interior space causes the simultaneous removal therefrom of the major part of the power storage slurry. Each outer electrode unit includes a generally planar gas electrode, a device for separating the metal particles from the gas electrode, and a device for preventing mechanical damage to the device for separating upon removal of the inner electrode unit from the interior space and upon insertion of the inner electrode unit into that space.

We claim: 
     
       1. An electrical power storage system comprising: an electrical power storage unit having at least one rechargeable electrical cell which comprises:   a pair of generally planar outer electrode means configured to define therebetween an interior space for an electrical power storage medium; and   inner electrode means removably mounted between said pair of outer electrode means so as to be in electrically conductive contact with said electrical power storage medium and defining a plurality of volumes each having a pair of open ends, each open end facing an adjacent outer electrode means; and   means for replacing a discharged volume of said electrical power storage medium with a charged volume of said electrical power storage medium,   wherein said cell is a metal-gas battery cell and said electrical power storage medium contained in said interior space comprises a bed of power storage slurry containing active metal particles saturated with an electrolyte solution, said pair of outer electrode means defines an opening communicating with said interior space, said plurality of volumes are configured to contain portions of the bed of slurry, and said inner electrode means is configured for removal from said interior space via said opening, thereby causing the simultaneous removal of the bed of slurry from said interior space, and   wherein said means for replacing a discharge volume comprises:   means for removing said inner electrode means from said interior space so as to remove therefrom the discharged volume of the electrical power storage medium,   means for immersing said inner electrode means in a body of charged slurry so as to enable the charged slurry to flow into and fill each of said plurality of volumes, and   means for replacing said inner electrode means in said interior space.   
     
     
       2. A system according to claim 1, and wherein the body of charged slurry is located in a container and said system also includes means for generating a flow of the charged slurry within said container so as to aid the filling of said plurality of volumes with the charged slurry.